+ Docker-based makefile targets for Buildroot

This commit is contained in:
Mingyang Li
2026-06-09 07:24:04 -07:00
parent 07fdf6c0d8
commit 5c532c865d
3 changed files with 177 additions and 7 deletions

36
Dockerfile.buildroot Normal file
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@@ -0,0 +1,36 @@
ARG BUILDROOT_PLATFORM=linux/amd64
# TODO: Update to Trixie once we catch up with upstream Buildroot.
FROM --platform=${BUILDROOT_PLATFORM} debian:bookworm
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update \
&& apt-get install -y --no-install-recommends \
bc \
bison \
build-essential \
bzip2 \
ca-certificates \
cmake \
cpio \
diffutils \
file \
flex \
gawk \
git \
libncurses-dev \
libssl-dev \
make \
patch \
perl \
python3 \
python3-dev \
rsync \
unzip \
wget \
xz-utils \
&& rm -rf /var/lib/apt/lists/*
WORKDIR /work
CMD ["bash"]

122
Makefile
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@@ -7,6 +7,12 @@ export ARCH=arm
DOCKER_IMAGE := buildbrain-builder:local
ROOTFS_VOLUME := buildbrain-brainux-rootfs
# Separate, leaner image for Buildroot. Based on debian:bookworm (GCC 12)
# which is compatible with the 2023.05-era Buildroot fork without any patches.
BUILDROOT_DOCKER_IMAGE := buildbrain-buildroot:local
ROOTFS_VOLUME := buildbrain-brainux-rootfs
BUILDROOT_VOLUME := buildbrain-buildroot-rootfs
BUILDROOT_OUTPUT_VOLUME := buildbrain-buildroot-output
.PHONY:
setup:
@@ -138,7 +144,7 @@ lilobuild:
liloclean:
make -C ./brainlilo clean
.PHONY: brainux brainux-umount-special brainux-clean
.PHONY: brainux brainux-umount-special brainux-clean buildroot_rootfs
brainux:
@if [ "$(shell uname)" != "Linux" ]; then \
echo "Debootstrap is only available in Linux!"; \
@@ -182,10 +188,10 @@ brainux-clean: brainux-umount-special
sudo rm -rf brainux
buildroot_rootfs:
make -C buildroot brain_imx28_defconfig
make -C buildroot -j 12
sudo mkdir -p buildroot_rootfs
sudo tar -C ./buildroot_rootfs -xf buildroot/output/images/rootfs.tar
make -C buildroot O=/work/buildroot_output brain_imx28_defconfig
make -C buildroot O=/work/buildroot_output
mkdir -p buildroot_rootfs
tar -C ./buildroot_rootfs -xf buildroot_output/images/rootfs.tar
image/sd.img: clean_work
./image/build_image.sh brainux sd.img 3072
@@ -215,6 +221,10 @@ datetag:
docker-build:
docker build --platform linux/amd64 -t $(DOCKER_IMAGE) -f Dockerfile .
.PHONY:
docker-buildroot-build:
docker build --platform linux/amd64 -t $(BUILDROOT_DOCKER_IMAGE) -f Dockerfile.buildroot .
.PHONY:
docker-uboot:
docker run --rm --platform linux/amd64 -v "$$PWD":/work -w /work $(DOCKER_IMAGE) \
@@ -249,3 +259,105 @@ docker-volume-create:
.PHONY:
docker-volume-rm:
docker volume rm $(ROOTFS_VOLUME) 2>/dev/null || true
.PHONY:
docker-buildroot-rootfs: docker-buildroot-volume-rm docker-buildroot-volume-create docker-buildroot-output-volume-create
docker run --rm --platform linux/amd64 --privileged \
-v $(BUILDROOT_OUTPUT_VOLUME):/work/buildroot_output \
-v $(BUILDROOT_VOLUME):/work/buildroot_rootfs \
-v "$$PWD":/work -w /work $(BUILDROOT_DOCKER_IMAGE) \
bash -lc "make buildroot_rootfs"
.PHONY:
docker-buildroot-menuconfig:
docker run --rm -it --platform linux/amd64 \
-v "$$PWD":/work -w /work $(BUILDROOT_DOCKER_IMAGE) \
bash -lc "rm -rf buildroot/output/build/buildroot-config && make -C buildroot brain_imx28_defconfig && make -C buildroot menuconfig"
# Run after docker-buildroot-menuconfig to persist customisations.
.PHONY:
docker-buildroot-savedefconfig:
docker run --rm --platform linux/amd64 \
-v "$$PWD":/work -w /work $(BUILDROOT_DOCKER_IMAGE) \
bash -lc "rm -rf buildroot/output/build/buildroot-config && make -C buildroot savedefconfig BR2_DEFCONFIG=configs/brain_imx28_defconfig"
.PHONY:
docker-buildroot-sd-image:
docker run --rm --platform linux/amd64 --privileged \
-v $(BUILDROOT_VOLUME):/work/buildroot_rootfs \
-v "$$PWD":/work -w /work $(DOCKER_IMAGE) \
bash -lc "make -C nkbin_maker clean all && make IMG_BUILD_JOBS=1 image/sd_buildroot.img"
# Fast rootfs-only update: replace only the ext4 partition (p2) in an existing
# sd_buildroot.img without rebuilding U-Boot (saves ~35 min per iteration).
# Requires image/sd_buildroot.img to already exist from a prior full build.
# Workflow for overlay-only changes:
# 1. Edit files under os-buildroot/override/
# 2. make docker-buildroot-rootfs (~1 min)
# 3. make docker-buildroot-patch-image (~1 min)
# 4. Flash image/sd_buildroot.img
.PHONY:
docker-buildroot-patch-image:
docker run --rm --platform linux/amd64 --privileged \
-v $(BUILDROOT_VOLUME):/work/buildroot_rootfs \
-v "$$PWD":/work -w /work $(DOCKER_IMAGE) \
bash -lc "set -e; \
KPARTX_OUTPUT=\$$(kpartx -av image/sd_buildroot.img); \
echo \"\$${KPARTX_OUTPUT}\"; \
LONAME=\$$(echo \"\$${KPARTX_OUTPUT}\" | sed -n 's/^add map \(loop[0-9]\+\)p2.*/\1/p' | head -1); \
if [ -z \"\$${LONAME}\" ]; then echo 'Failed to detect loop device from kpartx output'; exit 1; fi; \
mkdir -p /mnt/brainp2; \
mount /dev/mapper/\$${LONAME}p2 /mnt/brainp2; \
echo 'Wiping old rootfs...'; \
rm -rf /mnt/brainp2/*; \
echo 'Copying new rootfs...'; \
cp -a buildroot_rootfs/. /mnt/brainp2/; \
sync; \
umount /mnt/brainp2; \
kpartx -d image/sd_buildroot.img; \
echo 'Done. Rootfs partition updated.'"
# Fast kernel-only update: replace only boot partition (p1) kernel artifacts
# in an existing sd_buildroot.img, without rebuilding rootfs or repacking image.
# Requires image/sd_buildroot.img to already exist.
# Workflow for kernel-only changes:
# 1. make docker-kernel
# 2. make docker-buildroot-patch-kernel-image
# 3. Flash image/sd_buildroot.img
.PHONY:
docker-buildroot-patch-kernel-image:
docker run --rm --platform linux/amd64 --privileged \
-v "$$PWD":/work -w /work $(DOCKER_IMAGE) \
bash -lc "set -e; \
KPARTX_OUTPUT=\$$(kpartx -av image/sd_buildroot.img); \
echo \"\$${KPARTX_OUTPUT}\"; \
LONAME=\$$(echo \"\$${KPARTX_OUTPUT}\" | sed -n 's/^add map \(loop[0-9]\+\)p1.*/\1/p' | head -1); \
if [ -z \"\$${LONAME}\" ]; then echo 'Failed to detect loop device from kpartx output'; exit 1; fi; \
mkdir -p /mnt/brainp1; \
mount -o utf8=true /dev/mapper/\$${LONAME}p1 /mnt/brainp1; \
echo 'Updating kernel artifacts on boot partition...'; \
cp -f linux-brain/arch/arm/boot/zImage /mnt/brainp1/; \
cp -f linux-brain/arch/arm/boot/dts/imx28-pw*.dtb /mnt/brainp1/; \
sync; \
umount /mnt/brainp1; \
kpartx -d image/sd_buildroot.img; \
echo 'Done. Kernel artifacts updated.'"
.PHONY:
docker-buildroot-full: docker-kernel docker-buildroot-rootfs docker-buildroot-sd-image
.PHONY:
docker-buildroot-volume-create:
docker volume create $(BUILDROOT_VOLUME)
.PHONY:
docker-buildroot-volume-rm:
docker volume rm $(BUILDROOT_VOLUME) 2>/dev/null || true
.PHONY:
docker-buildroot-output-volume-create:
docker volume create $(BUILDROOT_OUTPUT_VOLUME)
.PHONY:
docker-buildroot-output-volume-rm:
docker volume rm $(BUILDROOT_OUTPUT_VOLUME) 2>/dev/null || true

View File

@@ -119,6 +119,12 @@ If you want to customize the build of Buildroot, `cd` into `buildroot` and use t
- `make menuconfig` to change the configuration
- `make` to build the rootfs (`-j` option might give you extra speed)
For Docker-based customization, use the interactive targets:
1. `make docker-buildroot-menuconfig`
2. `make docker-buildroot-savedefconfig` — writes `buildroot/.config` back to `buildroot/configs/brain_imx28_defconfig` so your changes are committed-safe.
3. `make docker-buildroot-rootfs` — rebuilds the rootfs with the updated config.
`image/sd_buildroot.img` target expects presence of the tarball at `buildroot/output/images/rootfs.tar`. You'll have to `clean` and rebuild every time you change the Buildroot's config before making the SD image.
@@ -158,6 +164,22 @@ You can build everything in Docker instead of preparing native Linux cross toolc
**Note:** `make docker-rootfs` (and thus `make docker-sd-image-full`) always deletes and recreates the named volume `buildbrain-brainux-rootfs` before building, so each rootfs build starts from a clean slate. To delete the volume manually between runs use `make docker-volume-rm`.
3. *(Optional)* Build a Buildroot-based SD image instead.
```sh
make docker-buildroot-full
```
This builds the Linux kernel, the Buildroot rootfs, and assembles `image/sd_buildroot.img`. Run each stage independently if preferred:
```sh
make docker-kernel
make docker-buildroot-rootfs
make docker-buildroot-sd-image
```
The Buildroot rootfs is stored in a separate named volume (`buildbrain-buildroot-rootfs`) for the same Linux-filesystem reasons as the Debian rootfs. `make docker-buildroot-rootfs` always recreates it from scratch; use `make docker-buildroot-volume-rm` to wipe it manually.
### Direct Docker commands (advanced)
For macOS, run in **stages** and use a **named volume** for the rootfs.
@@ -203,8 +225,8 @@ Other useful Docker recipes:
- `make docker-uboot` to build U-Boot
- `make docker-kernel` to build Linux kernel
- `make docker-volume-create` to (re-)create the rootfs named volume
- `make docker-volume-rm` to delete the rootfs named volume and reclaim its disk space
- `make docker-volume-create` / `make docker-volume-rm` to manage the Debian rootfs volume
- `make docker-buildroot-volume-create` / `make docker-buildroot-volume-rm` to manage the Buildroot rootfs volume
Known issues